Computer modeling studies of drug-induced sublethal damage have been carried out. A kinetic compartment model has been developed for the Sezary syndrome. In vitro studies of hydroxyurea-adriamycin and sangivamycin have been done. The effects of hydroxyurea in mouse marrow were studied. Artifacts of mithramycin staining have been identified in flow cytometry studies. Flow cytometry studies have been, and are being carried out in human lymphoma, melanoma, acute leukemia, and various other solid tumors in man.